<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title></title>
</head>

<body>
<form id="form1" name="form1" method="post" action="">
    <input type="text" name="t" id="t" />
</form>
<script>
var t = document.getElementsByTagName("input")[0]; 	// 获取文本框的引用指针
var f = document.getElementsByTagName("form")[0]; 	// 获取表单的引用指针
t.onchange = function(){
   f.submit(); 
}

</script>

</body>
</html>
